Various latex compositions can be used as binders for non-woven fabrics. In many applications, it is desirable for the latex binder composition to provide fire-retardant characteristics. For instance, in clothing and household applications, it is normally desirable for the latex employed to contain a fire-retardant material.
A wide variety of chemical agents can be used in latex binders as fire-retardants. For instance, tris-(2,3-dibromopropyl) phosphate was once widely used as a flame-retardant in manufacturing children's sleepwear. However, tris-(2,3-dibromopropyl) phosphate is no longer used in such applications because testing has showed that it might be carcinogenic. Other flame-retardant compounds that have been developed to replace tris-(2,3-dibromopropyl) phosphate include tris(1,3-dichloroisopropyl) phosphate and a mixture of two cyclic phosphonate esters.
U.S. Pat. No. 2,036,854 discloses that a mixture of ammonium borate or phosphate with an ammonium halide, such as ammonium bromide, is useful for flame-proofing textile materials. U.S. Pat. No. 2,036,854 further reports that the ammonium halide appears to greatly enhance the flame-extinguishing properties of the ammonium borate or phosphate.
U.S. Pat. No. 2,452,054 discloses the use of diammonium phosphate and ammonium bromide as a flame-retardant for use on cellulosic materials. It is further disclosed in U.S. Pat. No. 3,061,492 that ammonium bromide can be used as a flame-retardant for unsaturated polyester resin compositions.
U.S. Pat. No. 3,840,488 discloses the use of ammonium bromide and urea as flame-retardant additives for styrene-butadiene rubber (SBR) latex that is used for textile treatment and carpet backing applications. However, U.S. Pat. No. 3,840,488 further discloses that the utilization of ammonium bromide and urea in such latices has the undesirable effect of reducing the viscosity of the latex. The teachings of U.S. Pat. No. 3,840,488 further indicate that this undesirable decrease in the viscosity of the latex can be prevented by the addition of a halo alkyl phosphoric acid or salt.
U.S. Pat. No. 5,484,839 discloses a flame-retardant natural or synthetic latex which is grafted with ring-halogenated, ethylenically unsaturated aromatic monomers. These grafted latex compositions are reported to be useful as non-woven filter media binders, as backcoatings for woven upholstery and draperies, and in other applications.
U.S. Pat. No. 4,239,670 appreciates the fact that the addition of some flame-retardant materials, such as diammonium phosphate, to latex can cause the latex to become unstable. U.S. Pat. No. 4,239,670 further notes that such instability can render the latex unsuitable for its intended purpose. U.S. Pat. No. 4,239,670 solves the problem of latex instability caused by the addition of diammonium phosphate by further adding one part by weight of ammonium bromide per part by weight of diammonium phosphate added to the latex.